Hatz Biplane Association

The Hatz Classic plans show a control horn bumper stop at the tail that works for down elevator. There is, as far as I can tell from page 18, no stop for up elevator and no stops at the stick to supplement the back bumper. Without stops at the stick like those shown on the CB-1 plans and on the AcroSport II plans (snippet attached), I'm concerned that long-term, repeated hits between the bumper stop and horn may, and I stress may, lead to a crack at the horn. I may be paranoid but I decided to take the CB-1/AcroSport approach and install stick-based stops. I still need to get the right length bolt but as you can see in the attached pictures, the stops are easy to make, easy to adjust, and effective.

-Scott

Yes, control stops at the control stick are a good idea, otherwise the forces applied to the stick are transferred through all the control system tubing, etc. With the control stops at the stick the pilot applied forces end at the control stick and do not load the entire control system. Oddly my RV-4, in generally a well thought out plane, has all of the control stops near the control surfaces, so all the slamming to the stops that you might induce in aerobatics gets applied to everything..... Still hasn't broken though.